package org.xxpay.core.common.util;

import java.io.IOException;
import java.security.SecureRandom;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESKeySpec;

/**
 * DES加密 解密算法
 *
 * @author longhao
 */
public class MyDES {


    private final static String DES = "DES";
    private final static String ENCODE = "GBK";
    private final static String defaultKey = "test1234";

    static final MyLog _log = MyLog.getLog(MyDES.class);

    /**
     * key只有前8位生效
     */

    public static void main(String[] args) throws Exception {
        String data = "测试ss";
        String encrypt = encrypt("{\"type\":\"1\",\"content\":{\"message\":\"abc\"}}", "12345678");
        System.out.println(encrypt);
        System.out.println(decrypt(encrypt, "12345678"));
//        // System.err.println(encrypt(data, key));
//        // System.err.println(decrypt(encrypt(data, key), key));
//        System.out.println(encrypt(data));
//        System.out.println(decrypt(encrypt(data)));

    }

    /**
     * LDiFUdf0iew=
     *
     */

    /**
     * 使用 默认key 加密
     *
     * @return String
     * @author longhao
     * @date 2015-3-17 下午02:46:43
     */
    public static String encrypt(String data) throws Exception {
        byte[] bt = encrypt(data.getBytes(ENCODE), defaultKey.getBytes(ENCODE));
        String strs = MyBase64.encode(bt);
        return strs;
    }

    /**
     * 使用 默认key 解密
     *
     * @return String
     * @author longhao
     * @date 2015-3-17 下午02:49:52
     */
    public static String decrypt(String data) throws IOException, Exception {
        if (data == null)
            return null;
        byte[] buf = MyBase64.decode(data);
        byte[] bt = decrypt(buf, defaultKey.getBytes(ENCODE));
        return new String(bt, ENCODE);
    }

    /**
     * Description 根据键值进行加密
     *
     * @param data
     * @param key
     *            加密键byte数组
     * @return
     * @throws Exception
     */
    public static String encrypt(String data, String key)  {
        try {
            byte[] bt = encrypt(data.getBytes(ENCODE), key.getBytes(ENCODE));
            return new String(MyBase64.encode(bt));
        } catch (Exception e) {
            _log.error(e, "");
            return null;
        }

    }

    /**
     * Description 根据键值进行解密
     *
     * @param data
     * @param key
     *            加密键byte数组
     * @return
     * @throws IOException
     * @throws Exception
     */
    public static String decrypt(String data, String key)  {
        try {
            if (data == null)
                return "";
            byte[] buf = MyBase64.decode(data);
            byte[] bt = decrypt(buf, key.getBytes(ENCODE));
            return new String(bt, ENCODE);
        } catch (Exception e) {

        }
        return "";
    }

    /**
     * Description 根据键值进行加密
     *
     * @param data
     * @param key
     *            加密键byte数组
     * @return
     * @throws Exception
     */
    private static byte[] encrypt(byte[] data, byte[] key) throws Exception {
        // 生成一个可信任的随机数源
        SecureRandom sr = new SecureRandom();

        // 从原始密钥数据创建DESKeySpec对象
        DESKeySpec dks = new DESKeySpec(key);

        // 创建一个密钥工厂，然后用它把DESKeySpec转换成SecretKey对象
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES);
        SecretKey securekey = keyFactory.generateSecret(dks);

        // Cipher对象实际完成加密操作
        Cipher cipher = Cipher.getInstance(DES);

        // 用密钥初始化Cipher对象
        cipher.init(Cipher.ENCRYPT_MODE, securekey, sr);

        return cipher.doFinal(data);
    }

    /**
     * Description 根据键值进行解密
     *
     * @param data
     * @param key
     *            加密键byte数组
     * @return
     * @throws Exception
     */
    private static byte[] decrypt(byte[] data, byte[] key) throws Exception {
        // 生成一个可信任的随机数源
        SecureRandom sr = new SecureRandom();

        // 从原始密钥数据创建DESKeySpec对象
        DESKeySpec dks = new DESKeySpec(key);

        // 创建一个密钥工厂，然后用它把DESKeySpec转换成SecretKey对象
        SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(DES);
        SecretKey securekey = keyFactory.generateSecret(dks);

        // Cipher对象实际完成解密操作
        Cipher cipher = Cipher.getInstance(DES);

        // 用密钥初始化Cipher对象
        cipher.init(Cipher.DECRYPT_MODE, securekey, sr);

        return cipher.doFinal(data);
    }
}